The present invention relates to G-protein coupled receptor agonists. In particular, the present invention is directed to agonists of GPR 119 that are useful for the treatment of diabetes, especially type 2 diabetes, obesity, the metabolic syndrome and related diseases and conditions.
Diabetes is a disease derived from multiple causative factors. It is characterized by elevated levels of plasma glucose (hyperglycemia) in the fasting state or after administration of glucose during an oral glucose tolerance test. There are two generally recognized forms of diabetes. In type 1 diabetes, or insulin-dependent diabetes mellitus (IDDM), patients produce little or no insulin, the hormone which regulates glucose utilization. In type 2 diabetes, or noninsulin-dependent diabetes mellitus (T2DM), insulin is still produced in the body, and patients demonstrate resistance to the effects of insulin in stimulating glucose and lipid metabolism in the main insulin-sensitive tissues, namely, muscle, liver and adipose tissue. These patients often have normal levels of insulin, and may have hyperinsulinemia (elevated plasma insulin levels), as they compensate for the reduced effectiveness of insulin by secreting increased amounts of insulin.
Obesity is characterized by excessive adiposity relative to body mass. Clinically, obesity is defined by the body mass index [BMI=weight (kg)/height (m)2], corresponding to BMI values≧30. Obesity and being overweight increases the risk of developing conditions such as high blood pressure, type 2 diabetes, heart disease, stroke, osteoarthritis, sleep apnea, gallbladder disease and cancer of the breast, prostate and colon. Higher body weights are also associated with increases in all-cause mortality.
There is renewed focus on pancreatic islet-based insulin secretion that is controlled by glucose-dependent insulin secretion. In this regard, several orphan G-protein coupled receptors (GPCR's) have recently been identified that are preferentially expressed in the β-cell and are implicated in glucose dependent insulin secretion (GDIS). GPR119 is a cell-surface Gs-coupled GPCR that is highly expressed in human (and rodent) islets as well as in insulin-secreting cell lines. Synthetic GPR119 agonists augment the release of insulin from isolated static mouse islets only under conditions of elevated glucose, and improve glucose tolerance in diabetic mice and diet-induced obese (DIO) C57/B6 mice without causing hypoglycemia. GPR119 agonists therefore have the potential to function as anti-hyperglycemic agents that produce weight loss.